Lethality of Previous Suicidal Behavior among Patients Hospitalized for Suicide Risk Predicts Lethality of Future Suicide Attempts SASHA M. ROJAS, MA, KAYLA D. SKINNER, MA, MATTHEW T. FELDNER,PHD, DEMIAN E. RODANTE, MD, SOLEDAD PUPPO, MD, PATRICIA VIDJEN, MD, ALICIA PORTELA, MD, MSC, LEANDRO N. GRENDAS, MD, MSC, AND FEDERICO M. DARAY, MD, MSC,PHD Objective: A suicide attempt is an established risk factor for subsequent suicide attempts and suicide. Nonetheless, the prediction of future suicidal behavior is poor. The lethality of previous suicidal behavior may be informative to better understand future suicide risk among patients hospitalized for suicidal thoughts and behavior. The current study examined whether the lethality of patients’ index (most recent suicidal episode at hospitalization), first, and worst suicidal episode predicts the lethality of one’s most lethal suicide attempt during a 2-year follow-up period. Method: A total of 98 patients hospitalized at an emergency department for high suicide risk (i.e., acute suicidal ideation or a suicide attempt) were included in the study. Results: Results indicated that the lethality of the index suicidal episode predicted the lethality of the worst suicide attempt during a 2-year follow-up period. Conclusions: These findings extend a growing literature examining risk factors that influence the progression toward high lethality suicidal behavior. Suicidal behavior and suicide are long-stand- ing, complex problems that affect communities globally. Individuals who attempt suicide, or are deemed to be at high SASHA M. ROJAS AND KAYLA SKINNER, University of Arkansas, Fayetteville, AR, USA; MATTHEW T. FELDNER, University of Arkansas, Fayetteville, AR, USA and Laureate Institute for Brain Research, Tulsa, OK, USA; DEMIAN RODANTE, School of Medicine, Institute of Pharmacology, University of Buenos Aires, Paraguay, CABA, Argentina and “Dr. Braulio A. Moyano” Neuropsychiatric Hospital, Brandsen, CABA, Argentina; SOLEDAD PUPPO, School of Medicine, Institute of Pharmacology, University of Buenos Aires, Paraguay, CABA, Argentina and Hospital de Cl  ınicas “Jos e de San Mart  ın”, Av. C ordoba, CABA, Argentina; PATRICIA VIDJEN AND ALICIA PORTELA, Jos e Tiburcio Borda Hospital, Buenos Aires, CABA, Argentina; LEANDRO GRENDAS, School of Medicine, Institute of Pharmacology, University of Buenos Aires, Paraguay, CABA, Argentina; FEDERICO M. DARAY, School of Medicine, Institute of Pharmacology, University of Buenos Aires, Paraguay, CABA, Argentina and National Scientific and Technical Research Council (CONICET), Buenos Aires, CABA, Argentina. The authors want to gratefully acknowledge the study participants for their collaboration, the nursing staff, and field teams in each Hospital. This work was supported in part by a grant from Ministry of Science, Technology and Productive Innovation of Argentina (PIDC-2012-0064). No author or immediate family member has financial relation- ships with commercial entities that might appear to represent a potential for conflict of interests. All authors have approved the final article. Address correspondence to F. M. Daray, Instituto de Farmacolog  ıa, Facultad de Medic- ina, Universidad de Buenos Aires. Paraguay 2155, piso 9, C1121ABG, Ciudad de Buenos Aires, Argentina; E-mail: fdaray@hotmail.com Suicide and Life-Threatening Behavior 1 © 2018 The American Association of Suicidology DOI: 10.1111/sltb.12538